The extravaganza is expected to draw a whopping 115 million viewers — or about one in three Americans — and amounts to an unofficial holiday in the United States, where even those with no interest in the sport gather at countless Super Bowl parties.

This year's championship comes with the National Football League battling back from a season of turmoil, accused of complacency and even conspiracy in its handling of issues ranging from domestic violence to concussion dangers.

The latest controversy — accusations that the New England Patriots intentionally deflated footballs — has dominated news coverage in the days leading up to the game.

Controversy aside, Sunday is a chance for both teams to cement a place in Super Bowl lore with a victory.

Reigning champions Seattle Seahawks hope to become the first team to win back-to-back Super Bowls since the Patriots did so a decade ago, while New England is looking to be the sixth team to win four or more titles — a list led by Pittsburgh with six.

It is a dazzling matchup of old guard versus new, as veteran Patriots quarterback Tom Brady takes on 26-year-old Seattle signal-caller Russell Wilson. A clash of coaching styles will also be on display in cool-tempered Bill Belichick and enthusiastic Pete Carroll.

Frenzied fans partied Saturday night around Phoenix and near the University of Phoenix Stadium in suburban Glendale, Arizona, where the game is scheduled to kick off at 4:30 pm (23:30 GMT).

Something for everyone

Some novice football fans will be tuning in mostly for the much-anticipated halftime show, which this year features pop princess Katy Perry and rocker Lenny Kravitz.

Perry, known for her flamboyant costumes and hits like "Firework," "California Gurls" and "Dark Horse," hinted her performance could feature a surprise guest, but promised clean, family-friendly fun.

Past shows have been marred by infamous nipple-baring "wardrobe malfunctions" or crude gestures that provoked ire from some of the massive television audience.

Over nachos, chili and beer, viewers will also see much-buzzed about commercials, some of the most expensive air time on the market, with this year's line-up featuring spots from Toyota, Budweiser and Victoria's Secret.

More than 70 advertisers are paying a reported $4.5 million for 30 seconds of air time during Sunday's football classic.

Scandal trails Pats

The Patriots will take the field trailing a whiff of scandal, with the league still investigating whether they purposely deflated footballs to gain an advantage in their playoff triumph over Indianapolis on January 18.

Maddie Meyer/Getty Images For critics, "Deflategate" is further proof that Belichick's glittering post-season resume has been built on the back of rules bent to breaking point.

But even those put off by Belichick's gruff demeanor find it hard to argue with his five Super Bowl rings -- two as the defensive coordinator for the New York Giants and three as head coach of the Patriots.

Carroll, on the surface, is the warm and fuzzy opposite of reserved Belichick, but has produced Seahawks teams that even the Patriots coach admires for their "relentlessness."

Now, Carroll's Seahawks will try to usurp the Patriots' throne as the league's dominant team, gained with Super Bowl titles in 2002, 2004 and 2005.

Brady can join his boyhood idol Joe Montana and Terry Bradshaw as the only quarterbacks with four Super Bowl wins.

The legacy of 37-year-old Brady is secure no matter what the outcome on Sunday, with a league-leading 49 touchdowns and 7,017 passing yards in the post-season.

His excellence has belied his unheralded entrance into the league in 2000, when New England took him in the sixth round of the entry draft, 199th overall.

Outstripping expectations

Otto Greule Jr/Getty Images Wilson, Brady's opposite number in Seattle, has also outstripped expectations since being drafted in the third round in 2012.

Considered by many NFL experts too small at 5-foot-11 (1.80 meters) to play the position effectively, Wilson outshone Denver's future Hall-of-Famer Peyton Manning in last year's Super Bowl.

To be sure, Wilson was aided then, as he will be now, by the Seahawks' punishing defense, which has proven capable of dismantling the league's finest attacks.

Nevertheless, the Seahawks still bring the fire of underdogs, even a Super Bowl triumph failing to erase the sting of being overlooked on draft day.